1. Field of the Invention
This invention relates to the germination of seeds and more specifically to an apparatus and method for hydroponically growing sprouts in a controlled environment.
2. Description of the Prior Art
Various types of apparatuses and methods have been utilized to sprout and grow vegetables, grasses and other plants hydroponically, i.e. without the use of soil. Such apparatuses commonly utilize large trays or containers in which seeds are initially placed and then periodically moistened to facilitate germination and growth. A stationary, rectangular shaped frame structure is generally provided for supporting the trays in vertical stacks. Examples of such structures are disclosed by Lund, U.S. Pat. Nos. 2,169,701; Perlin, 2,725,673; Finck, 3,991,514; Lund, Great Britain Pat. No. 473,012; La Culture Sans Terre S.A., Great Britain Pat. No. 1,176,753; Gordon, Great Britain Pat. No. 1,374,076; and, Gruber, German Offenlegungsschrift No. 2,602,788. Since all of these patents utilize rather large containers for germinating the seeds and growing the seedlings, subsequently packaging the seedlings into convenient consumer size quantitites for distribution involves a time consuming, expensive additional operation.
The growing trays and their associated frame structures have, in some instances, been placed within enclosed housings with the air within the housing maintained at a constant temperature by either heating or cooling. Examples of such heated housings are disclosed by the aforementioned patents to Lund 2,169,701 and 473,012, Perlin 2,725,673, Finck 3,991,514 and Gruber 2,602,788.
Artificial lights have been employed to facilitate the growth of the plants once they have germinated. In the Gruber 2,602,788 Offenlegungsschrift, artificial lights are disposed vertically along the inside of surface of the housing wall while in the Finck 3,991,514 patent the lights are disposed horizontally along the inside surface of the housing wall. A shortcoming resulting from placing lights only along the interior walls of the housing is that light is not uniformly distributed throughout the housing so that the farther a plant is located from the housing walls, the less light the plant will receive. Another type of lighting installation is disclosed by Lund, U.S. 2,169,701 patent wherein lights are disposed along the ceiling of the housing. Placing the lights in this location, however, only permits plants in the uppermost trays of the stack of trays to receive light.
In some apparatuses for hydroponically growing plants, the irrigation water is recirculated. Attempts have been made to filter the recirculated water to remove contaminates such as seed hulls, fragments of roots, fungus or mold spores. In the above mentioned Finck, 3,991,514 and Gordon, 1,374,076 patents, a filter is placed in the water line between the nozzles used to discharge the water onto the growing plants and the pump used to pump water to the nozzles. Merely filtering the irrigation water, however, has not prevented the growth of fungus or mold within the warm, moisture laden environment in which plants are typically hydroponically grown. Often fungicides and other chemicals must be added to the water to adequately control fungus problems. For example, the Finck, 3,991,514 patent discusses adding a fungicide known as alkyl dimethyl benzyl ammonium chloride to the water to reduce the growth of fungus within the chamber walls.
Another type of apparatus for sprouting seeds is disclosed by Yoo, U.S. Pat. No. 3,768,201 wherein a single container is supported within a larger chamber. The larger chamber also serves as a storage container for water used to periodically spray the seeds and sprouts located within the smaller container. A heating coil is located within the bottom portion of the larger container to heat the water stored therein. Also, artificial light bulbs are disposed along the ceiling of the larger chamber to shine downwardly on the plants located within the container to foster photosynthesis of the sprouted seeds.